Combustion engine oil pan

ABSTRACT

A combustion engine oil pan including a sump capable of containing oil and a sole configured to compliment the sump, able to support, with sealing, the sump and to be fixed to the engine, particularly a bottom or low part of the engine, wherein the join between the sump and the sole extends to form notched cutouts in the sole and in the sump.

The invention relates to the technical field of oilpans for combustion engines notably of motor vehicles.

It is known that hybrid oilpans allow a lightening of the engine and therefore an improvement in the performance of the vehicle thus equipped.

Hybrid oilpans made of aluminum and sheet metal, i.e. which comprise a lower sump bottom made of relatively flat sheet metal and a complementary aluminum sump housing supporting the sump bottom and fixed to the engine, are known. These pans may be able to support vehicle components, such as the gearbox or the air-conditioning compressor.

A motor vehicle combustion engine hybrid oilpan in which the plastic sump bottom is fixed to a sump housing made of lightweight metal is also known, the sump bottom being intended to contain the engine oil in a relatively planar configuration and the sump housing being configured in a complementary way in connection with the engine, namely more or less in the form of a rectangular parallelepiped. These oilpans may be able to support vehicle components, such as the gearbox, and prove to be more lightweight than the aluminum and sheet metal oilpans described above.

There is a need for a vehicle combustion engine oilpan that is even lighter still.

The invention proposes an oilpan for a combustion engine, comprising a sump housing and a sump bottom. This sump housing is intended to be fixed to the engine on the one hand and to the sump bottom of the oilpan on the other, and is configured to further support vehicle components. This sump housing comprises a lower bearing edge for sealed connection with a complementary bearing edge of the sump bottom. The bearing edge for sealed connection comprises at least one wide notch in at least one lateral wall of the sump housing.

Thus, by virtue of such a stepped arrangement, the sump housing is of a more open, holed design than the sump housings of the prior art which have a substantially planar lower bearing edge. The lower bearing edge of the sump housing extends in all three directions, rather than in a plane as in the prior art. The sump housing can thus be reduced at least in part to a simple framework, of relatively light weight. The sump housing may have top parts and bottom parts, the bottom parts corresponding to particular requirements connected with the functionalities of the sump housing. For example, a bottom part may be provided for supporting a component of the timing cover type.

Such a sump housing is also configured to encircle the bottom part of the engine or the bottom of the engine, with a geometry which fits the bottom of the engine, contains less material that a conventional oilpan sump housing, of substantially rectangular parallelepipedal shape, and in this way the oilpan is lightened relative to a conventional oilpan.

The sump housing and the sump bottom thus have complementary shapes and fit into one another to form the oilpan.

The bearing edge of the sump housing and the bearing edge of the sump bottom may extend around the entire periphery of the sump housing and of the sump bottom respectively.

Each wide notch, also referred to in the present application as a notch, may occupy all or part of one side of the sump housing, or even several adjacent sides of the sump housing. The lateral wall of the sump housing corresponding to any one given side may have one or several notches.

A wide notch in a wall of the sump housing means that the wall is cut out with a significant variation in the lower bearing edge of the wall relative to a substantially planar hypothetical lower edge. The height of the cutout may represent 5% or more of the maximum height of the walls of the sump housing, advantageously 15% or more, advantageously 30% or more, and advantageously 50% or more.

A “vehicle component” means the components likely to be supported at least in part by the oilpan, such as the gearbox, the timing cover or the air-conditioning compressor for example.

The terms lower and upper, bottom and top, vertical and horizontal, are to be considered within the common meaning of the term when the sump housing is oriented as it needs to be for mounting in a vehicle. Thus, the gravity vector is a vertical vector perpendicular to the horizontal planes and running from the top downwards.

This sump housing may advantageously comprise the parts for attaching the oilpan to the engine, particularly to the bottom of the engine.

This sump housing may thus advantageously comprise at least one reinforcing plate for supporting a heavy part of the vehicle, for example a front plate or a rear plate, able to support an engine timing cover, a compressor or a vehicle gearbox.

A sump housing as described hereinabove is also proposed.

Also proposed is a sump bottom for an oilpan for a combustion engine, this sump bottom being intended to contain oil and to be fixed to a sump housing itself designed to be fixed to the engine and also to support at least one vehicle component. The sump bottom is characterized in that its upper bearing edge, intended to form a sealed connection with a lower bearing edge of the sump housing, comprises at least one wide notch in at least one lateral wall of the sump bottom.

This sump bottom therefore has walls that are taller than others and may form with the sump housing described hereinabove a relatively lightweight hybrid oilpan.

Each notch may occupy all or part of one side of the sump bottom, or even several adjacent sides of the sump bottom. The lateral wall of the sump bottom corresponding to a given side may have one or more notches. The walls may therefore, at certain points, have heights which are less than the nominal oil level once the oilpan has been assembled under the engine block and has been filled. The “nominal level” means that the oil level is between a minimum and a maximum both prescribed by the manufacturer. The pan is thus configured to take a quantity of oil such that at least part of the complementary bearing edge for sealed connection of the sump bottom lies below the level of the oil contained in the oilpan.

The sump bottom may advantageously be formed with a shell made of plastic, and this makes the sump bottom even lighter still in comparison with a sheet metal sump bottom.

The plastic of which the shell is made may be a conventional polyamide but may also be filled with glass fiber, carbon fiber or the like to increase its mechanical strength.

The shell is advantageously molded.

The shell may advantageously comprise at least some of the components associated with the treatment of the oil are formed as one piece with the shell, for example oil circuit ducts and treatment components for circulating, decanting, filtering or cooling the oil, for example ducts of the oil supply circuit with the built-in oil pump, ducts of the oil filter circuit with the oil filter support element, ducts of the oil decanting circuit with the decanting chambers, heat exchanger circuits, etc.

Thus there is no need to perform machining operations for these components as there is with the aforementioned known oilpan sump bottoms.

Furthermore, it is easy to create at least some of the parts of the associated components by molding, for example the oil exchanger valve support, oil level sensor, oil pump control connector parts, etc.

The plastic shell may thus comprise, in addition to an oil sump bottom part proper, extension parts made as one with the shell and able to accept or constitute at least some of the components associated with the treatment of the oil, for example the oil circuit ducts leading to the oil feed pump, the oil decanting circuit ducts, the oil filtration ducts, the oil circuit ducts leading to the exchanger, etc., and also some parts of the associated components, for example the oil pump, the oil decanting chambers and component support pieces, while at the same time also ensuring that the various interfaces, such as, for example, the oil filter support element interface, are sealed.

Another result of this is also that, compared with the aforementioned known oilpan sump bottoms, there is no longer any need to mount on the sump bottom the various aforementioned parts of the components associated with treating the oil as these are already incorporated into the shell or body of the sump bottom. The oilpan is therefore easier and quicker to fit.

The shell may comprise an interior surface and an exterior surface, the interior surface being the surface intended to come into contact at least partially with the oil.

The plastic shell is advantageously configured with a ribbed or grooved geometry, the exterior surface advantageously being cellular. Such geometries may allow the shell to be given rigidity and robustness, for example for acoustic quietness when the engine is running (absence of vibration response) and for resistance to motoring impacts, hitting rocks, curbs, etc.

The ribbing described hereinabove may advantageously be performed on the vertical or near vertical peripheral surface (relative to the direction of mounting on the engine) of the wall of the shell. This ribbing or grooving may comprise uniform or non-uniform surface undulations.

The pan may advantageously be a hybrid oilpan, which means one in which the sump bottom and the sump housing are made of different materials. The sump bottom may be made of a material that is more lightweight than that of the sump housing, and the sump housing is made of a material that is stronger than that of the sump bottom. For example, the sump housing may be made of aluminum or aluminum alloy, while the sump bottom may be made of plastic.

The pan may advantageously have an elastomer gasket positioned between the sump housing and the sump bottom.

This gasket extends in a sealed manner between the upper bearing edge of the sump bottom and the lower bearing edge of the sump housing. This gasket may seal the assembly of the sump bottom and of the sump housing of the pan when the latter is fixed to the engine.

This gasket also, through its geometry with cutout in space (non-planar geometry) makes it possible to attenuate the vibrations of the pan device when the engine is running. The gasket is arranged above or below the level of oil in the sump bottom so as to maximize the use of plastic in order to save weight.

The invention is not in any way limited by the shape of the profile of the gasket or by the material or materials used. The gasket may for example have a T-shape or some other profile. The gasket may be made of silicone elastomer, for example of linear poly(dimethylsiloxane) or PDMS, and/or of one or more other material(s).

In addition, the bearing edges of the sump bottom and/or of the sump housing that are in contact with the elastomer gasket may be left unfinished, as-molded in the case of the sump bottom, and as-cast in the case of the sump housing. The plastic of the sump bottom body and the flexible elastomer gasket absorb any imperfections of the edge surfaces in contact with the gasket. In consequence, the machining of these surfaces, as in conventional hybrid oilpans, may be optional.

The invention also proposes a motor vehicle engine comprising an oilpan as described hereinabove.

Also proposed is a method for using the pan described hereinabove. In particular, the method may advantageously involve a step of partially filling the pan with a quantity of oil that is sufficient that at least part of the complementary bearing edge for sealed connection of the sump bottom is situated below the level of the oil contained in the pan.

One embodiment of the invention is now described by way of nonlimiting example with reference to the attached drawings in which:

FIG. 1 is an exploded perspective view of one example of a hybrid oilpan according to one embodiment of the invention, and

FIG. 2 is a perspective view of the oilpan of FIG. 1 in the assembled state.

With reference to the figures, the oilpan 1 depicted comprises a lower (relative to the direction of mounting) sump bottom 2 able to contain oil for a combustion engine and an upper metal sump housing 5 intended to be fixed to the bottom part (engine bottom), not depicted, of a combustion engine for a motor vehicle.

The lower sump bottom 2 comprises a shell 3, molded from plastic, for example polyamide. This material is able to withstand the high temperature of the oil when the engine is running, from 100 to 140° C. approximately.

The shell 3 comprises an actual sump bottom proper 7 containing the engine oil and extension parts 9, also molded in, able to accept or constitute components associated with the oilpan in the treatment of the oil, for example an oil duct circuit 11 positioned adjacent to the sump bottom 7 and comprising ducts 13 carrying the oil to a water/oil heat exchanger 15.

Other elements are fixed to the shell, for example an oil filter bowl 17 by a filter supply duct molded into the body (not depicted), an oil filter valve 19 via a molded support part (not depicted), an oil level sensor 21 that senses the oil level in the sump bottom via a molded support part 22, an oil drain plug via a molded support part (not depicted), an oil pump control connector 23 via a molded support part (24).

The shell 3 is ribbed 25 on its vertical and horizontal peripheral wall surface and this increases its rigidity, its ability to withstand impact, hitting rocks and curbs for example, and allows for acoustic quietness when the engine is running. The shell 3 comprises an interior surface in contact with the oil, and an exterior surface.

According to one embodiment that has not been depicted, the shell 3 may on its exterior surface have a network of cells to increase impact resistance and further improve acoustic quietness.

As depicted in the figures, an upper bearing edge 37 of the sump bottom extends as a top stage in relation to a lower bearing edge 40 so as to form two cutouts in the two opposing walls of greater length, which are formed as notches 42 relative to the cutouts 40 in the opposing walls of shortest length. The walls of the sump bottom are therefore of open, holed, design.

The upper sump housing 5 is made of light metal, molded or cast in aluminum for example. This sump housing 5 is configured to complement the sump bottom 2, like a connecting belt connecting the low or bottom part of the engine and the sump bottom 2, and extending around the bottom of the engine to the periphery thereof.

A lower bearing edge 35 of the sump housing has a shape substantially identical to that of the upper bearing edge 37, 40 of the sump bottom. Thus, this lower bearing edge 35 forms two cutouts in the walls corresponding to the two opposing sides of longest length of the sump housing and comprises a notch 36 on the walls corresponding to the two opposing sides of shortest length of the sump housing. The complementary edge 37 of the sump bottom may therefore at certain points lie below the level of the oil contained in the oilpan once the oilpan has been mounted under the engine block and has been filled.

An elastomer gasket 33 is interposed between the sump housing 5 and the lower sump bottom 2 when the sump bottom and the sump housing are assembled with one another (using bolts). The gasket 33 is pressed respectively between the lower peripheral edge 35 of the sump housing 5 and the corresponding upper application edge 37, 40 of the periphery of the sump bottom body 2.

This gasket 33 extends in space (is not flat) so that it follows the cutout geometry of the sump bottom 2 and of the sump housing 5, and in particular, the gasket 33 has two opposing parts, a front part 39 and a rear part 41, which are stepped downward relative to the more extensive longitudinal parts 43 of this gasket 33.

The gasket 33 may be mounted on the application edges 35, 37, 40 and 42 of the sump housing 5 and of the sump bottom 2 which are left as-cast and/or as-molded, the plastic of the body of the sump bottom being able to absorb, in combination with the elastomer gasket, the imperfections of the edge of the sump housing.

According to one embodiment, this gasket 33 may be made of elastomer with a T-shaped profile, and the bearing edge of the sump bottom 2 may be configured to define a groove able to accept the upright of the T of the gasket 33.

A rear part in the form of plate 27 (to the right in the drawing) of this sump housing is more extensive and more rigid. This part 27 may have the vehicle gearbox (not depicted) attached to it. Other elements, not depicted, may be attached to this sump housing. For example, an engine timing cover may be attached to part of a front plate 29, and a vehicle air-conditioning compressor may be attached to one of the walls corresponding to the sides of longer length.

The parts 31 for attachment to the bottom of the engine, notably bores that accept the bolts for attachment to the engine, are formed in the upper part of the sump housing.

The invention is not restricted to the embodiments described hereinabove. For example, the gasket 33 may be made of silicone applied to the bearing edge of the sump bottom 2 without the need for a groove in this edge, or the gasket 33 may comprise several pieces made of elastomer or of silicone.

The foregoing demonstrates the advantages of a vehicle combustion engine oilpan according to one embodiment of the invention, with a lightened sump housing, a sump bottom molded from plastic with a configuration incorporating components associated with the oilpan, particularly the oil circuit leading to the heat exchanger, the oil supply circuit, the oil filter circuit, etc. It is thus possible to exercise freedom in how the supporting sump housing is configured relative to ancillary attachment elements, particularly the vehicle gearbox, the vehicle air-conditioning compressor, the engine timing cover, etc. These advantages also include the saving of weight on the oilpan and the ease with which the assembly can be produced and fitted compared with a conventional hybrid oilpan. 

1-10. (canceled)
 11. An oilpan for a combustion engine, comprising: a sump housing and a sump bottom; the sump housing configured to be fixed to the engine and to the sump bottom of the oilpan, and configured to further support vehicle components, the sump housing comprising a lower bearing edge for sealed connection with a complementary bearing edge of the sump bottom, wherein the bearing edge for sealed connection comprises at least one wide notch in at least one lateral wall of the sump housing.
 12. The oilpan as claimed in claim 11, wherein the oilpan is configured to take a quantity of oil such that at least part of the complementary bearing edge for sealed connection of the sump bottom lies below a level of the oil contained in the oilpan.
 13. The oilpan as claimed in claim 11, wherein the sump housing comprises at least one reinforcing plate for supporting part of the vehicle.
 14. The oilpan as claimed in claim 11, further comprising an elastomer gasket arranged between the lower bearing edge of the sump housing and the complementary bearing edge of the sump bottom.
 15. The oilpan as claimed in claim 11, wherein the sump bottom comprises a shell made of plastic.
 16. The oilpan as claimed in claim 15, wherein the shell is molded and comprises at least some of components associated with treatment of oil that are formed as one piece with the shell.
 17. The oilpan as claimed in claim 15, wherein the plastic shell is configured with a ribbed or grooved geometry, and an exterior surface of the shell is cellular.
 18. The oilpan as claimed in claim 15, wherein the bearing edges of the sump bottom shell and of the sump housing that are in contact with the elastomer gasket are left unfinished, as-molded in a case of the sump bottom, and as-cast in a case of the sump housing.
 19. The oilpan as claimed in claim 11, wherein the sump bottom and the sump housing are made of different materials.
 20. A motor vehicle comprising: an engine and an oilpan for the engine as claimed in claim
 11. 